Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
톨레미의 이론은 고대 천문학에서 중요한 역할을 했다.Tollemiui ilheon-eun godae cheonmunhakeseo jungyohan yeoghal-eul haetta.The Ptolemaic theory played an important role in ancient astronomy.